Upper frame-equipped foldable stepladder

Abstract

[Problem] To provide an upper frame-equipped foldable stepladder which can be folded into an easy-to-carry shape. [Solution] When an upper frame-equipped foldable stepladder is folded, a support leg 50L, a support leg 50R, a top plate 20, a step 30, and a bar 44 of an upper frame 40 all become parallel to each other. Further, the top plate 20 and the step 30 are housed in a hollow part of the support leg 50L in a state of being arranged side by side in the extension direction (vertical direction) of the support leg 50L. The bar 44 of the upper frame 40 does not vertically protrude beyond the support leg 50L and the support leg 50R.

Description

Folding stepladder with upper frame

[0001] The present invention relates to a folding stepladder with a top frame.

[0002] BACKGROUND ART Conventionally, a folding stepladder in which the step legs can be folded inside the support legs has been known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2001-349612

[0004] The folding stepladder described in Patent Document 1 can be folded so that the steps are stored inside the support legs. This allows it to be more compact than when in use. However, in the folding stepladder described in Patent Document 1, the support legs are vertically offset even when the folding stepladder is folded. This makes the length of the stepladder longer than when it is folded.

[0005] Furthermore, stepladders with upper frames are known to prevent users from becoming unstable when standing on the top of the stepladder, etc. However, stepladders with upper frames end up being longer when folded than stepladders without upper frames.

[0006] To provide a folding stepladder with an upper frame that can be folded into a shape that is easy to carry and whose length when folded is not longer than that before folding.

[0007] According to one aspect of the present invention, there is provided a folding stepladder with an upper frame, comprising: two ladders; and a hinge pivotably connecting the two ladders, wherein the two ladders each comprise: a first hollow support leg extending in a first direction, the first support leg having a first pin and a second pin spaced apart from each other from one side to the other in the first direction; a second hollow support leg extending in the first direction, the second support leg having a third pin and a fourth pin spaced apart from each other from the one side to the other in the first direction; a top plate pivotably connected at one end to the first pin of the first support leg, the top plate having a first rail slidably connected to the third pin of the second support leg; and a step pivotably connected at one end to the third pin of the first support leg, the step having a second rail slidably connected to the fourth pin of the second support leg. The top plate and the steps are movable in conjunction with each other between a storage position where they are stored in the hollow portion of the first support leg in a state parallel to the first direction, and a use position where the first support leg and the second support leg are connected in a state parallel to a second direction perpendicular to the first direction, one of the two ladders further comprises an upper frame having: a first support pillar rotatably connected at one end to the first support leg; a second support pillar rotatably connected at one end to the second support leg; and a bar member rotatably connected to one of the first support pillar and the second support pillar, the upper frame being rotatable between a first position where the other end of the first support pillar and the other end of the second support pillar protrude in the first direction beyond the first support leg and the second support leg, and a second position where the other end of the first support pillar and the other end of the second support pillar do not protrude in the first direction beyond the first support leg and the second support leg, A folding stepladder with an upper frame is provided, characterized in that when the upper frame is in the second position, the bar member is movable between a first position parallel to the first direction and a second position connecting the first support pole and the second support pole in a state parallel to the second direction.

[0008] When the folding stepladder with an upper frame of the present invention is folded, the first support leg, the second support leg, the top plate, the steps, and the bar members of the upper frame are all parallel. This allows the length in the second direction of the folding stepladder to be compact when folded. Furthermore, the top plate and the steps are stored in the hollow portion of the first support leg while aligned in the direction of extension of the first and second support legs. The upper frame is also folded so that it does not protrude from the first and second support legs. This makes the folding stepladder with an upper frame easy to carry. Furthermore, when the folding stepladder with an upper frame is folded, the length in the first direction of the folding stepladder with an upper frame is the same as the length in the first direction of the first support leg, so the folding stepladder with an upper frame can be folded compactly.

[0009] Fig. 1 is a schematic diagram showing the folding stepladder with upper frame 1 in use. Fig. 2 is a schematic explanatory diagram showing the folding stepladder with upper frame 1 in a folded state. Fig. 3 is a schematic diagram for explaining the second shape of the folding stepladder with upper frame 1. Fig. 4 is a schematic diagram for explaining an intermediate state between the second shape and the third shape of the folding stepladder with upper frame 1. Fig. 5 is a schematic diagram for explaining the third shape of the folding stepladder with upper frame 1. Fig. 6 is a schematic diagram for explaining the folding stepladder with upper frame 1 according to a modified embodiment.

[0010] A folding stepladder with an upper frame 1 according to an embodiment of the present invention will be described with reference to the drawings. In this specification, directions are defined based on the front-to-rear, up-down, and left-to-right directions indicated by arrows in Figure 1, and the left-to-right and up-to-down directions indicated by arrows in Figure 2.

[0011] Fig. 1 is a schematic diagram showing a folding stepladder with an upper frame 1 in use. Fig. 2 is a schematic explanatory diagram showing the folding stepladder with an upper frame 1 in a folded state.

[0012] As shown in FIG. 1 , the folding stepladder with head frame 1 of this embodiment includes a first ladder 11 having a head frame 40 and a second ladder 12. The second ladder 12 has the same structure as the first ladder 11, except that the second ladder 12 does not have a head frame 40. The first ladder 11 and the second ladder 12 correspond to the two ladders of the present invention. In FIG. 1 , the first ladder 11 is positioned in front of the second ladder 12. The first ladder 11 and the second ladder 12 are connected by a hinge 13. This allows the folding stepladder with head frame 1 to be folded in the front-to-rear direction so that the first ladder 11 and the second ladder 12 come into contact with each other (see FIG. 3 ). FIG. 3 is a schematic explanatory diagram showing the state in which the folding stepladder with upper frame 1 is folded in the front-rear direction so that the first ladder 11 and the second ladder 12 are in contact with each other with the upper frame 40 folded downward.

[0013] 1, a locking mechanism 14 is provided between the first ladder 11 and the second ladder 12 to prevent the first ladder 11 and the second ladder 12 from opening too far when in use. The locking mechanism 14 includes a long, plate-like hook plate 14a with a U-shaped groove at one end, a pin 14b that rotatably fixes the other end of the hook plate 14a to the second ladder 12, and a locking pin 14c provided on the first ladder 11 that fits into the U-shaped groove of the hook plate 14a. The opening angle between the first ladder 11 and the second ladder 12 can be fixed by fitting the locking pin 14c into the U-shaped groove of the hook plate 14a.

[0014] Next, we will explain the structure of the first ladder 11. The structure of the second ladder 12 is the same as that of the first ladder 11 except for the presence or absence of the upper frame 40, so we will not explain it again.

[0015] 1, the first ladder 11 includes a top board 20, rungs 30, an upper frame 40, and a pair of support legs 50. In the following description, the left support leg of the pair of support legs 50 will be referred to as support leg 50L, and the right support leg will be referred to as support leg 50R.

[0016] <Tabletop 20> The tabletop 20 is a substantially rectangular parallelepiped member that spans the upper end portions of the pair of support legs 50. A rail 121 (an example of a first rail of the present invention) extending in the left-right direction is provided on the front outer wall portion of the tabletop 20 (see FIG. 3). The rail 121 is fitted with a rail pin 151 (an example of a third pin of the present invention) fixed to the support leg 50L. This allows the tabletop 20 to be slidably connected to the support leg 50L. Furthermore, the right end of the tabletop 20 is rotatably attached to the support leg 50R by a rotation axis pin 152 (an example of a first pin of the present invention) fixed to the support leg 50R.

[0017] <Step 30> As shown in Figure 3, the step 30 is a hollow, approximately rectangular parallelepiped member that spans the approximate center of the pair of support legs 50. Similar to the tabletop 20, a rail 131 (an example of a second rail of the present invention) extending in the left-right direction is provided on the front outer wall of the step 30. The rail 131 is fitted with a rail pin 153 (an example of a fourth pin of the present invention) fixed to the support leg 50L. This allows the step 30 to be slidably connected to the support leg 50L. The right end of the step 30 is rotatably connected to the support leg 50R by a rotation axis pin 154 (an example of a third pin of the present invention) fixed to the support leg 50R.

[0018] <Upper Frame 40> As shown in Figures 1 and 3, the upper frame 40 includes a pair of support columns 42 and a bar 44. The left support column of the pair of support columns 42 is referred to as support column 42L, and the right support column is referred to as support column 42R. The bar 44 is a hollow member having a generally rectangular parallelepiped shape that spans the upper ends of the pair of support columns 42. A rail 141 (an example of a third rail of the present invention) extending in the left-right direction is provided on the rear outer wall portion of the bar 44. The rail 141 is fitted with a rail pin 143 (an example of a sixth pin of the present invention) fixed to the support column 40L. This allows the bar 44 to be slidably connected to the support column 42L. The right end of the bar 44 is rotatably connected to the support leg 50R by a rotation axis pin 144 (an example of a fifth pin of the present invention) fixed to the support column 40R.

[0019] As shown in FIG. 1 , the lower end of the support column 42L is rotatably fixed to the support leg 50L via a pivoting portion 46, and the lower end of the support column 42R is rotatably fixed to the support leg 50R via a pivoting portion 46. The upper frame 40 is rotatable between a first position (see FIG. 1 ) in which the pair of support columns 42 are substantially parallel to the pair of support legs 50 and the bar 44 protrudes above the tabletop 20, and a second position (see FIG. 3 ) in which the pair of support columns 42 are substantially parallel to the pair of support legs 50 and the bar 44 does not protrude beyond the support legs 50. To prevent the upper frame 40 from accidentally rotating when the upper frame 40 is in the first position shown in FIG. 1 , a locking mechanism 15 for preventing rotation is provided between the support leg 50 of the first ladder 11 and the support column 42 of the upper frame 40. The structure of the locking mechanism 15 is similar to that of the locking mechanism 14 described above, and therefore a description thereof will be omitted.

[0020] <Method of Folding the Folding Stepladder with Top Frame 1> Next, a method of folding the folding stepladder with top frame 1 will be described. When the folding stepladder with top frame 1 is in use, as shown in FIG. 1 , the locking mechanism 14 fixes the opening angle between the first ladder 11 and the second ladder 12. The locking mechanism 15 also fixes the top frame 40 to the first ladder 11 so that the top frame 40 remains in the first position, i.e., so that the top frame 40 does not rotate from the first position to the second position. This shape is referred to as the first shape of the folding stepladder with top frame 1 (see FIG. 1 ). As shown in FIG. 1 , in the first ladder 11 in the first shape, the top plate 20, the steps 30, and the bar 44 of the top plate 40 are all horizontal. This position of the top plate 20 and the steps 30 is referred to as the use position.

[0021] To fold the folding stepladder 1 with a top frame in the first shape, first, the hook plate 14a is removed from the lock pin 14c to unlock the locking mechanism 14. Similarly, the locking mechanism 15 is also unlocked. The top frame 40 is then rotated downward so that it is in the second position. The folding stepladder 1 with a top frame is then folded forward and backward so that the rear end of the first ladder 11 and the front end of the second ladder 12 are in contact with each other. At this time, the folding stepladder 1 with a top frame is folded downward and is folded forward and backward so that the first ladder 11 and the second ladder 12 are in contact with each other (see FIG. 3). This shape is called the second shape of the folding stepladder 1 with a top frame (see FIG. 3). When changing the folding stepladder 1 with upper frame from the first shape to the second shape, the order of rotating the upper frame 40 and folding the first ladder 11 and the second ladder 12 does not matter. In the second shape, the upper frame 40 is folded downward and does not protrude vertically beyond the support legs 50. The bars 44 of the upper frame 40 are horizontal (parallel to the top plate 20 and the steps 30). This position of the bars 44 of the upper frame 40 is called the first position.

[0022] The subsequent process of folding the folding stepladder with upper frame 1 is performed by interlocking the first ladder 11, the second ladder 12, and the upper frame 40 with the first ladder 11 and the second ladder 12 overlapping in the front-to-rear direction and with the upper frame 40 in the second position. Therefore, the following description will focus on folding the first ladder 11 with reference to Figures 3 to 5.

[0023] 4, the support leg 50R is moved upward so as to rotate the tabletop 20, the tread 30, and the upper frame 40 counterclockwise around the rail pins 151, 153, and 143 and the rotation axis pins 152, 154, and 144. As a result, the support leg 50R is positioned higher than the support leg 50L, and the left-right distance between the support leg 50L and the support leg 50R is shorter than in the second shape described above.

[0024] The support leg 50R is moved further upward so as to rotate the tabletop 20, step 30, and upper frame 40 counterclockwise around the rail pins 151, 153, and 143 and the rotation axis pins 152, 154, and 144. As a result, the support legs 50L and 50R, the tabletop 20, step 30, support posts 42L and 42R, and the bar 44 are all parallel in the vertical direction. At this time, the rail 121 of the tabletop 20, the rail 131 of the step 30, and the rail 141 of the upper frame 40 are also parallel in the vertical direction. At this time, the rail pin 151 of the support leg 50L is located at the lower end of the rail 121 of the tabletop 20. Similarly, the rail pin 153 of the support leg 50L is located at the lower end of the rail 131 of the step 30, and the rail pin 141 of the support post 40L is located at the lower end of the rail 141. The upper end of the support leg 50R is located higher than the upper end of the support leg 50L. In this case, the vertical length of the folding stepladder with upper frame 1 is longer than the vertical length of the folding stepladder with upper frame 1 in the second shape.

[0025] Then, the support leg 50R is slid downward so that the rail pin 151 of the support leg 50L slides upward along the rail 121 of the top plate 20. At this time, the rail pin 153 of the support leg 50L slides upward along the rail 131 of the step 30, and the rail pin 141 of the support post 40L slides upward along the rail 141 of the bar 44. This allows the first ladder 11 and the second ladder 12 to change into the third shape (see FIG. 5 ). As shown in FIG. 5 , in the third shape, the upper ends of the support legs 50L and 50R are positioned vertically in the same position, and the lower ends of the support legs 50L and 50R are positioned vertically in the same position. In other words, the vertical length of the folding stepladder 1 with an upper frame in the fourth shape is the same as the vertical length of the folding stepladder 1 with an upper frame in the second shape. Note that the expression "same length (or position)" does not mean that they are strictly the same. Although not shown in Figure 5, in the third shape, the tabletop 20 and the step 30 are housed in the hollow portion of the support leg 50L and are arranged side by side in the vertical direction in Figure 5. The position of the tabletop 20 and the step 30 in the third shape is called the housed position. Also, the bar 44 is housed in the hollow portion of the support column 42L. The position of the bar 44 at this time is called the second position.

[0026] <Effects of this embodiment> When the folding stepladder with upper frame 1 of this embodiment is folded, the support legs 50L, 50R, the top panel 120 of the top panel 20, the steps 30, and the upper frame 40 are all parallel to one another. Furthermore, the top panel 20 and the steps 30 are stored in the hollow portion of the support leg 50L while aligned in the extension direction (vertical direction) of the support legs 50L and 50R. Furthermore, the upper frame 40 is folded downward, so the upper frame 40 does not protrude vertically from the support leg 50. This makes the folding stepladder with upper frame 1 easy to carry. When the folding stepladder with upper frame 1 is folded, the ends of the support legs 50L and 50R are aligned. Furthermore, because the upper frame 40 is also folded downward, the vertical length of the folding stepladder with upper frame 1 is the same as the support legs 50L and 50R. Since the upper frame 40 is folded, the vertical length is shorter than that when the folding stepladder with upper frame 1 is in use. In this way, the folding stepladder with upper frame can be folded compactly.

[0027] <Modifications> The configuration of the head-framed folding stepladder 1 according to the present invention is not limited to the configuration in the above embodiment and can be modified in various ways. For example, in the above embodiment, the first ladder 11 and the second ladder 12 of the head-framed folding stepladder 1 each have one step 30. However, the arrangement and number of steps are not limited to this configuration. For example, the first ladder 11 and the second ladder 12 of the head-framed folding stepladder 1 may each have two steps, or may each have three or more steps. Furthermore, the number of steps provided on the first ladder 11 and the second ladder 12 does not have to be the same.

[0028] In the above embodiment, the bar 44 of the upper frame 40 was slidably connected to the support column 42L. The rail pin 141 of the support column 40L slid along the rail 141 of the bar 44, thereby moving the bar 44 so that it was housed in the cavity of the hollow portion of the support column 42L. However, the present invention is not limited to such an embodiment. For example, as shown in FIG. 6 , one end of the bar 44 may be rotatably connected to the support column 40L via a rotation axis pin 146. The other end of the bar 44 may be provided with a hook portion 48 configured to engage with an engagement portion 49 provided on the support column 40R. In this case, the bar 44 can be positioned horizontally by engaging the hook portion 48 of the bar 44 with the engagement portion 49. In this case, a locking mechanism (not shown) may be provided to prevent the hook portion 48 and the engagement portion 49 from easily coming apart. In this embodiment, the operation of accommodating the bar 44 into the cavity of the hollow portion of the support column 40L and the operation of sliding the tabletop 20 and the step 30 to accommodate them into the cavity of the hollow portion of the support leg 50L can be performed independently. Therefore, compared to the case where the bar 40, tabletop 20, and step 30 are slid simultaneously as in the above embodiment, the number of components that must be slid simultaneously is reduced, making it easier to slide the tabletop 20 and step 30 to accommodate them into the cavity of the hollow portion of the support leg 50L.

[0029] The above-described embodiments and their modifications can be combined as appropriate. Furthermore, the shape, material, etc. of the folding stepladder with upper frame 1 according to the present invention are not limited to specific ones and can be changed as appropriate. For example, the folding stepladder with upper frame 1 can be made of iron or aluminum. It does not necessarily have to be made of a metal material, and can also be made of a non-metallic material such as wood or plastic. Furthermore, metal materials and non-metallic materials can be combined as appropriate.

[0030] 1 Folding stepladder with upper frame 11 First ladder 12 Second ladder 20 Top plate 30 Step 40 Upper frame 50 Support leg

Claims

1. A folding stepladder with a top frame, comprising two ladders and a hinge that rotatably connects the two ladders, wherein the two ladders each comprise: a first hollow support leg extending in a first direction, the first support leg having a first pin and a second pin spaced apart from each other from one side to the other in the first direction; a second hollow support leg extending in the first direction, the second support leg having a third pin and a fourth pin spaced apart from each other from the one side to the other in the first direction; a top plate rotatably connected at one end to the first pin of the first support leg, the top plate having a first rail slidably connected to the third pin of the second support leg; and a step rotatably connected at one end to the third pin of the first support leg, the step having a second rail slidably connected to the fourth pin of the second support leg. The top plate and the steps are movable in conjunction with each other between a storage position where they are stored in the hollow portion of the first support leg in a state parallel to the first direction, and a use position where the first support leg and the second support leg are connected in a state parallel to a second direction perpendicular to the first direction, one of the two ladders further comprises an upper frame having: a first support pillar rotatably connected at one end to the first support leg; a second support pillar rotatably connected at one end to the second support leg; and a bar member rotatably connected to one of the first support pillar and the second support pillar, the upper frame being rotatable between a first position where the other end of the first support pillar and the other end of the second support pillar protrude in the first direction beyond the first support leg and the second support leg, and a second position where the other end of the first support pillar and the other end of the second support pillar do not protrude in the first direction beyond the first support leg and the second support leg, A folding stepladder with an upper frame, characterized in that when the upper frame is in the second position, the bar member is movable between a first position in which the bar member connects the first support pole and the second support pole parallel to a second direction perpendicular to the first direction, and a second position parallel to the first direction.

2. A folding stepladder with an upper frame as described in claim 1, wherein one of the first support column and the second support column has a fifth pin and the other of the first support column and the second support column has a sixth pin, the bar of the upper frame is rotatably connected at one end to one of the first support column and the second support column by the fifth pin, and the bar of the upper frame has a third rail slidably connected to the sixth pin.

3. A folding stepladder with an upper frame as described in claim 1, wherein the other of the first support pole and the second support pole has an engaging portion that engages with a hook portion provided at one end of the bar.

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